Effect of acid catalysts on carbonization temperatures for ordered mesoporous carbon materials

Effect of acid catalysts on carbonization temperatures for ordered mesoporous carbon materials

Highly ordered mesoporous carbon (OMC) materials have attracted much attention in many fields including catalysis, adsorption and energy storage, due to their high porosity, high surface area and controllable regular pore-structure [1-6]. Successful synthesis pathways for obtaining OMC materials include the direct synthesis of OMC materials through the organic-organic self-assembly method (soft templating process) and nano-replication of OMC materials from mesoporous silica templates (hard templating process) [7-11]. The direct synthesis method is suitable for large-scale production of carbon materials due to its easier process compared to the nano-replication method [7,8]. However, the nano-replication method has still several advantages for synthesizing OMC materials. It is possible to synthesize various kinds of mesostructured OMC materials, which can be controlled by the mesostructure of the silica templates [12,13]. In addition, the morphology of OMC materials can also be varied with the silica templates using desired morphologies [12-14]. More importantly, various kinds of carbon precursors including sucrose, furfural, p-toluene sulfonic acid (p-TSA) and phenanthrene [14-17] can be used to control the physicochemical properties of the OMC materials, for which the nature of the carbon precursors affects the conductivity, porosity and surface functionality of the carbon frameworks [17-19]. However, nano-replication methods for OMC materials, based on a conventional thermal process at high temperature (typically above 900°C), are time- and energy-consuming processes. In order to oligomerize or polymerize the carbon precursors before the carbonization, an aging process should also be carried out in the presence of acid catalysts in low temperature ranges of 100°C?200°C. In the case of sucrose as a carbon source, sulfuric acid (H2SO4) is typically used as an acid catalyst for the dehydration and subsequent oligomerization of the carbon precursor. This is very im